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Development of a Generic PDA Based Control Mechanism for in-house Fabricated Miniature SensorsKedia, Sunny 19 November 2004 (has links)
A novel method of controlling miniature sensors using Handspring Visor Prism PDA has been implemented. A generic motherboard was developed to map the data and address lines from the Visor onto a Complex Programmable Logic Device (CPLD) to provide basic electrical signals to the sensor board. The sensor board housed the sensor and contained application specific circuitry. The PDA, the motherboard, and the sensor board completed the control mechanism for the sensor. Miniature sensors and PDA based control mechanism scaled down the size of the complete system making the unit portable. This unit facilitated a faster analysis of data on field. Two applications were targeted: Flurometer (bio-sensor) and Corner Cube Retroreflector (CCR-optical sensor for communication). A sensor board was developed to control a thermally regulated fluorometer undergoing the Nuclei Acid Synthesis Based Amplification (NASBA) process, which detected the fluorescence from the solution containing target RNA. NASBA runs were conducted using solution containing K. brevis- Red tide organisms to validate the interface of the PDA with a fluorometer. Real time fluorescence plot over time was obtained on the PDA indicating presence/absence of the target RNA; thus, it successfully interfaced the PDA with the fluorometer. Additionally, a sensor board was developed to control the electrostatic actuation mechanism of the MEMS based CCR. Efforts were made to fabricate the vertical mirrors of CCR using wet and dry fabrication techniques.
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Biogeochemical characterization of metalliferous wastes and potential role of arbuscular mycorrhizae in their phytoremediationChaudhry, Tariq M., University of Western Sydney, Faculty of Informatics, Science and Technology January 1999 (has links)
Phytoremediation is an innovative technology employing plants for reclamation of soils that have been polluted by industrial contaminants. While it is frequently slower than traditional physicochemical remediation techniques, there are, however, many significant advantages including simplicity, low cost, improvement of soil structure and microbiological fertility. While various hyperaccumulators have been reported from Europe and the USA, there is a need to identify Australian species. This study reports a number of metal accumulators following a soil and vegetation survey of two metal contaminated sites in New South Wales, the spoil (filtercake) heaps of the BHP (Broken Hill Propriety ) steelworks at Port Kembla and the abandoned mine at Sunny Corner. BHP is the largest manufacturer of steel in Australia. The Port Kembla is the largest single steel manufacturing site. Solid by-products from this site totalled 3.1 million tons in 1988. The Sunny Corner mine site was mainly a silver mine which operated over approximately 100 hectares 1184 to 1922 and produced over 100 tonnes of silver during that period. The soil and water in and around the site is heavily contaminated with metals and is distinctly acidic. It was concluded that Ricinus communis, Sonchus oleraceus, baeckea utilis, Poa labillardieri and Pinus radiata are options for heavy metal phytoremediation of contaminated Australian soils. Arbuscular Mycorrhizal infection (particular with Glomus and Gigaspora strains) should be promoted for optimum growth. / Doctor of Philosophy (PhD)
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Camera Based Navigation : Matching between Sensor reference and Video imageOlgemar, Markus January 2008 (has links)
<p>an Internal Navigational System and a Global Navigational Satellite System (GNSS). In navigational warfare the GNSS can be jammed, therefore are a third navigational system is needed. The system that has been tried in this thesis is camera based navigation. Through a video camera and a sensor reference the position is determined. This thesis will process the matching between the sensor reference and the video image.</p><p>Two methods have been implemented: normalized cross correlation and position determination through a homography. Normalized cross correlation creates a correlation matrix. The other method uses point correspondences between the images to determine a homography between the images. And through the homography obtain a position. The more point correspondences the better the position determination will be.</p><p>The results have been quite good. The methods have got the right position when the Euler angles of the UAV have been known. Normalized cross correlation has been the best method of the tested methods.</p>
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Feature extraction based on a tensor image descriptionWestin, Carl-Fredrik January 1991 (has links)
<p>Feature extraction from a tensor based local image representation introduced by Knutsson in [37] is discussed. The tensor representation keeps statements of structure, certainty of statement and energy separate. Further processing for obtaining new features also having these three entities separate is achieved by the use of a new concept, tensor field filtering. Tensor filters for smoothing and for extraction of circular symmetries are presented and discussed in particular. These methods are used for corner detection and extraction of more global features such as lines in images. A novel method for grouping local orientation estimates into global line parameters is introduced. The method is based on a new parameter space, the Möbius Strip parameter space, which has similarities to the Hough transform. A local centroid clustering algorithm is used for classification in this space. The procedure automatically divides curves into line segments with appropriate lengths depending on the curvature. A linked list structure is built up for storing data in an efficient way.</p> / Ogiltigt nummer / annan version: I publ. nr 290:s ISBN: 91-7870-815-X.
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The Zaremba problem with singular interfaces as a corner boundary value problemHarutjunjan, Gohar, Schulze, Bert-Wolfgang January 2004 (has links)
We study mixed boundary value problems for an elliptic operator A on a manifold X with boundary Y / i.e., Au = f in int X, T±u = g± on int Y±, where Y is subdivided into subsets Y± with an interface Z and boundary conditions T± on Y± that are Shapiro-Lopatinskij elliptic up to Z from the respective sides. We assume that Z ⊂ Y is a manifold with conical singularity v. As an example we consider the Zaremba problem, where A is the Laplacian and T− Dirichlet, T+ Neumann conditions. The problem is treated as a corner boundary value problem near v which is the new point and the main difficulty in this paper. Outside v the problem belongs to the edge calculus as is shown in [3].
With a mixed problem we associate Fredholm operators in weighted corner Sobolev spaces with double weights, under suitable edge conditions along Z {v} of trace and potential type. We construct parametrices within the calculus and establish the regularity of solutions.
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Conormal symbols of mixed elliptic problems with singular interfacesHarutjunjan, G., Schulze, Bert-Wolfgang January 2005 (has links)
Mixed elliptic problems are characterised by conditions that have a discontinuity on an interface of the boundary of codimension 1. The case of a smooth interface is treated in [3]; the investigation there refers to additional interface conditions and parametrices in standard Sobolev spaces. The present paper studies a necessary structure for the case of interfaces with conical singularities, namely, corner conormal symbols of such operators. These may be interpreted as families of mixed elliptic problems on a manifold with smooth interface. We mainly focus on second order operators and additional interface conditions that are holomorphic in an extra parameter. In particular, for the case of the Zaremba problem we explicitly obtain the number of potential conditions in this context. The inverses of conormal symbols are meromorphic families of pseudo-differential mixed problems referring to a smooth
interface. Pointwise they can be computed along the lines [3].
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Exploiting individual wheel actuators to enhance vehicle dynamics and safety in electric vehiclesJonasson, Mats January 2009 (has links)
This thesis is focused on individual wheel actuators in road vehicles intended for vehicle motion control. Particular attention is paid to electro-mechanical actuators and how they can contribute to improving vehicle dynamics and safety. The employment of individual wheel actuators at the vehicle's four corner results in a large degree of over-actuation. Over-actuation has a potential of exploiting the vehicle's force constraints at a high level and of controlling the vehicle more freely. One important reason for using over-actuated vehicles is their capability to assist the driver to experience the vehicle as desired. This thesis demonstrates that critical situations close to the limits can be handled more efficiently by over-actuation. To maximise the vehicle performance, all the available actuators are systematically exploited within their force constraints. Therefore, force constraints for the individually controlled wheel are formulated, along with important restrictions that follow as soon as a reduction in the degrees of freedom of the wheel occurs. Particular focus is directed at non-convex force constraints arising from combined tyre slip characteristics. To evaluate the differently actuated vehicles, constrained control allocation is employed to control the vehicle. The allocation problem is formulated as an optimisation problem, which is solved by non-linear programming. To emulate realistic safety critical scenarios, highly over-actuated vehicles are controlled and evaluated by the use of a driver model and a validated complex strongly non-linear vehicle model. it is shown that, owing to the actuator redundancy, over-actuated vehicles possess an inherent capacity to handle actuator faults, with less need for extra hardware or case-specific fault-handling strategies. / QC 20100722
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Performance Characterization of Silicon-On-Insulator (SOI) Corner Turning and Multimode Interference DevicesZheng, Qi 05 September 2012 (has links)
Silicon-on-insulator (SOI) technology has become increasingly attractive because of the strong light confinement, which significantly reduces the footprint of the photonic components, and the possibility of monolithically integrating advanced photonic waveguide circuits with complex electronic circuits, which may reduce the cost of photonic integrated circuits by mass production. This thesis is dedicated to numerical simulation and experimental performance measurement of passive SOI waveguide devices. The thesis consists of two main parts. In the first part, SOI curved waveguide and corner turning mirror are studied. Propagation losses of the SOI waveguide devices are accurately measured using a Fabry-Perot interference method. Our measurements verify that the SOI corner turning mirror structures can not only significantly reduce the footprint size, but also reduce the access loss by replacing the curved sections in any SOI planar lightwave circuit systems. In the second part, an optical 90o hybrid based on 4 × 4 multimode interference (MMI) coupler is studied. Its quadrature phase behavior is verified by both numerical simulations and experimental measurements.
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Analysis Of Corner Effects On In-situ Walls Supporting Deep Excavations: Comparison Of Plane Strain And Three Dimensional AnalysesUnlu, Guliz 01 December 2008 (has links) (PDF)
In this thesis, hypothetical cases of in-situ walls, that are supported at one, two and
four levels, as well as cantilever walls, are analyzed using plane strain and 3D
finite element programs. A parametric study is performed by varying the soil
stiffness. Deflection, moment, anchor loads and effective lateral earth pressures
acting on the walls are examined to understand corner effect. Comparisons are
made between plane strain and 3D without corner analysis results to confirm that
two programs yield similar results. Moreover, two deep excavation case histories
namely: i) Ankara Ç / ankaya trade center and residence and, ii) Ekol construction
are analyzed using calibrated models. Calibrations of the models are made using
inclinometer data.
In hypothetical models, it is found that corner effects on deflections diminish after
20m distance from the corner for excavations that are 8m and 12m deep. Corner
effects on deflection decrease as elastic modulus of soil or stiffness of the system
increase. Moment diagram pattern changes along the excavation side in cantilever
case study. Moment diagram obtained around a corner in 3D analysis and
diagrams obtained from the plane strain analyses by modeling the corner as a strut
are quite similar. The anchor loads increase until 10-15m distance from the corner.
After this distance they become nearly constant.
In the analysis of case histories, a trial error solution is adopted to fit the deformed
shape of piled wall obtained from 3D analysis to the deformations recorded by
inclinometers. These results are compared with the results of plane strain
analyses. Ankara-Ç / ankaya project is solved by modeling the corner as strut in
plane strain analyses. Results of this analyze agrees with field monitoring data,
indicating that corner effects could be simulated by modeling the perpendicular pile
wall as a strut in plane strain analysis.
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Characterization of Multi-Gate Partially-Depleted SOI MOSFET with MESA IsolationHuang, Kuo-Ying 20 July 2001 (has links)
Abstract
In this thesis, a Multi-gate PD SOI Device is realized. The inverse narrow channel effect of the device is also studied.
In the Multi-gate PD SOI structure, it has three-surface gate on the silicon MESA Island, which can promote the device performance. However, for eliminating the abnormal corner leakage current in the MESA Island, the process of rounded corner is used. In order to overcome the floating body effect, we use the Schottky body contact. According to the 3-D DAVINCI device simulation and the measurement results, the Multi-gate PD SOI device presents the excellent characteristics: low threshold voltage, low subthreshold factor and high breakdown voltage. In addition, comparing the Multi-gate device with that of the conventional one, the excess drain current gain is observed.
In order to understand the behavior of INCE in Multi-gate PD SOI Device in depth, we use the concept of overlap depletion region to derive the expressions of threshold voltage shift. Owing to the device has rounded corner, we also study the rounded corner effect in the model formulation. Comparing calculation with that of the experiment one, the calculation shows agreement with the experiments.
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